"I got people to start evacuating inside from our little garden that we have ... and got people to come in to the bar and to go into toilets, hide under tables and hide in our cellar where we keep all our stock," Lamas said. Before police arrived he said he saw three attackers repeatedly stab a man who was on the ground.
At another restaurant in Borough Market, witnesses said that an attacker entered and stabbed a woman in the neck, and a manager threw bottles at the man and staff used a bar stool to push him outside.
"I just watched the football game and a guy came in holding a massive knife and stabbed a girl by the door," a witness, who would not give his name, told NBC News.
More from NBC News:
London Bridge Attack: 6 Killed, 48 Wounded; 3 Suspects Shot Dead by Police
London Bridge Attack: Why Most U.K. Police Don't Carry Guns
Londoners Ran, Hid and Fought Attackers Amid Van and Stabbing Rampage
Police responded to reports of a vehicle striking pedestrians on London Bridge at around 10:08 p.m. local time (5:08 p.m. ET) Saturday, London's Metropolitan Police said. Stabbings were then reported at nearby Borough Market, armed police responded and shots were fired, police said.
Six people were killed and police shot and killed three suspects, police said early Sunday local time. More than 30 people were taken to hospitals, the ambulance service said.
As the violence unfolded, police were quick to tell anyone they came across to clear the area, witnesses said. And they also told them to run.
"I was just walking past Borough Market, and I saw loads of people start running," Simon Thompson told NBC News. "A taxi driver rolled down his window and started screaming, 'Keep running, keep running — people have been stabbed.'" Thompson said he saw some injured people on the ground.
Thompson, 24, was pulled into a restaurant where he hid with others in a basement and could see people on the street via security cameras. They heard gunfire and were later told by authorities that they were in an unsafe area and evacuated.
"Armed police were shooting outside but at the point I didn't know if it was police or who," said Alcolea, who added that she had a panic attack. "The police then threw gas canisters into the bar and everyone was told to put their hands up above their heads and file out of the bar."
Witnesses near the gunfire described panic, with police ordering bystanders to places of safety. "I was at Bank Station, the walls are curved and this policeman with a massive gun told us to go right up against the wall, there was a woman next to me screaming, it was terrifying," one witness told NBC News.
The terror attacks in London comes nearly two weeks after a suicide bomber killed 22 people and wounded dozens more outside an Ariana Grande concert in Manchester. Grande and other musicians are scheduled to perform at a benefit concert in Manchester on Sunday.
Grande tweeted: "Praying for London" Saturday night.
After the Manchester bombing the nation raised its terror alert to "critical," the highest possible level. After several arrests were made, the threat level was lowered to "severe."
U.S. President Donald Trump condemned the attack and said the United States would do whatever it can to assist the United Kingdom.
Saphora Smith and Chloe Hubbard reported from London. Phil McCausland reported from New York.